I am getting a "Radeon Freesync not supported" for my LG 27UD58P-B monitors. I am using display ports on GIGABYTE Radeon RX 5700 XT.
by any chance, do you have Freesync enabled on both your LG and in Radeon Settings?
LG has a very new Onscreen Control software for your monitor: LG 27UD58P-B.AUS: Support, Manuals, Warranty & More | LG USA Support
From your monitor's manual on enabling Freesync:
I recommend using the extended mode of FreeSync with Windows 10, this seems to work best with both GeForce and Radeon cards.
My RX 480 with DP is plugged into an LG 4K panel
Monitor's OSD -> Menu -> Picture -> Game Adjust -> Freesync Enabled.
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